In Team Foundation Server 2010, when trying to create a new Workspace to an existing project, the following error occurs:
"$<Source_Control_Path> is not a valid source control folder"
Example:
$/Apps_Toad/SQL/Release/DB1 is not a valid source control folder
WORKAROUND:
Select the $/ (root) as the source control folder, which will allow different workspaces assigned to the same project.
STATUS:
Issue fixed in version 12.0. The latest version of Toad for Oracle can be downloaded here.